1. Field of the Invention
The present invention relates generally to a transaction processing system, and more specifically to a transaction processing system represented by an electronic cash register equipped in a super-market, for instance to register commodities sold.
2. Description of the Prior Art
As is well known, electronic cash registers (referred to as ECRs) are equipped in a department store or a super-market in order to register commodities bought by customers. In the conventional ECRs, there is provided a unit commodity management file which stores unit cost data for each unit commodity code and unit sales data (the number of commodities sold, the total amount of sales money, etc.) for each unit commodities code. Further, in the conventional ECRs, whenever a unit commodity code is entered, a unit cost data corresponding to the entered unit commodity code is read from the unit commodity management file to inplement registration processing, and further unit sales data (the number of commodities sold, the total amount of commodities sold or total amount of sales money) are updated in the unit commodity management file.
Here, assumption is made that a unit commodity code is given to a ball-point pen of 100 yen per piece. In this case, since the ball-point pens are classified into two, black and red, for example, kinds, there exists a problem in that it is impossible to grasp the amount of commodities sold or the amount of commodities to be stocked according to colors of the ball-point pens, even if the ball-point pens are registered on the basis of only unit commodity code (without classifying the pens according to colors).
To overcome the above-mentioned problems, it is possible to subdivide a unit commodity and to give a commodity code to each subdivided commodity before registering the sales data. The above-mentioned codes each assigned to each subdivided articles are called article codes. However, when these article codes are adopted, there exists another problem in that a management file of huge capacity must be provided for each ECR, independently.
Further, it is also possible to enter only unit commodity codes when subdivision is not required and to enter subdivided commodity codes only where necessary. In this case, however, there still exists another problem in that an additional key must be depressed to enter the subdivided commodity codes different from the unit commodity codes, and therefore the number of keys is increased and the key depression operation is further complicated.